1. Field of the Invention
The present invention generally relates to generator base tanks performing the dual function of auxiliary generator support and fuel storage and, more particularly, is concerned with a distortion-resistant generator support base and storage tank assembly.
2. Description of the Prior Art
In the past decade or so, a need has developed to maintain auxiliary generators on standby for deployment at hospitals and other sites to provide auxiliary electrical power in the case of blackouts and other outages. Because of Environmental Protection Agency (EPA) regulations and other environmental requirements, such auxiliary generators are designed to have their fuel storage tanks located above ground but directly beneath and supporting the generator.
Heretofore, these generator base support fuel storage tanks have been rectangular in configuration so as to provide a horizontal load bearing top surface for mounting and supporting the generator. The generator base tanks are generally of two constructions. One construction provides a single wall tank which meets a predetermined internal pressure requirement. Another construction provides a double wall tank which has a primary inner tank for containing the fuel and a secondary outer tank which is capable of containing the fuel of the primary tank in case of rupture thereof. In the double wall tank, there are two separate sidewalls spaced apart on all sides except for the top wall which is of a single thickness. These generator base tanks are also known in the trade as secondary containment generator base tanks or closed or open top diked generator base tanks, depending upon other particular features of the tanks.
Due to numerous testing requirements, such as internal pressure testing, the sidewalls of the rectangular tank tend to buckle and distort in shape. Tested rectangular tanks which have become distorted still remain safe. However, such distortion is not only objectionable from an appearance standpoint, it also frequently causes field inspectors to reject such tanks and prohibit their further use even though they are still safe. In response to the distortion problem, tank manufacturers have tended to overbuild tank structures by using heavier gauge metal than required and by using reinforcing bars and gussets that add extra material costs and time-consuming and costly manufacturing steps to produce these tanks. This response to the distortion problem is not a satisfactory solution.
Consequently, a need exists for a different approach to the design of generator base tanks to solve the tank distortion problem.